LTO cells on Batteryhookup.com

[erik.calco]

That would be much better but I and Will still recommend 12

My inverter and current bank is 24V. There'd be no benefit to doing 12V for me. If anything, I'd go to 48V one day, but never down to 12V.

EDIT: Oh, you mean 12S.

 

[Craig]

My inverter and current bank is 24V. There'd be no benefit to doing 12V for me. If anything, I'd go to 48V one day, but never down to 12V.

I mean 12S not 12V

 

[Craig]

Please dont get me wrong I like these batteries I just want people aware that 10S is not enough to power 24 volts with full capacity

 

[erik.calco]

I mean 12S not 12V

Yeah, I did an edit before you posted. lol

But why 12S instead of 11S? You are trying to squeeze a tiny bit more capacity or just think it will work with more inverters that can't go as low on the cutoff?

 

[Craig]

Honestly I do not know if it matters I just like to keep voltage above 24 at all times seems like less work on inverter. Also its a round number. I dont remember why I decided 12 instead of 11 but I know I thought about it for a while. Plus with 10P that little extra energy will add up to a lot.

 

[erik.calco]

Based on your data, the 1.83 to 1.99 range includes 8% of your total. So, that might be what you can squeeze out of the bottom end with 12S instead of 11S, IF you don't give it up on the top end. And this assumes I used 22V cutoff instead of 20.4V, to be able to run in parallel with LFP.

EDIT: The LV2424 can cutoff as low as 20V, not 20.4V. This expands the bottom of the cell range to 1.81V with 11S.

 

[Craig]

Once I figure out how to display it properly I plan to put all my data out so people can see . Also notice in my spreadsheet that each cell differs a bit in its "sweet spot" of max power output.

 

[erik.calco]

Once I figure out how to display it properly I plan to put all my data out so people can see . Also notice in my spreadsheet that each cell differs a bit in its "sweet spot" of max power output.

If you are looking at 12V, then 6S certainly makes more sense. But, 11S can work well with 24V. I personally don't like getting too close to the lower limit of cells. I'd rather have a buffer down there for one-off situations.



Why did you only go up to 2.49V?

There will be a big diff in upper cutoff on whether your are adding to an LFP bank or running independently. As I look at those numbers, the case for running these as a separate bank increases. Then you have to think about how to optimize loads with two separate banks.

I can do it. But, that takes its own planning.

I haven't thought about it, but it is also possible for one bank to become a reserve for another. That gets complicated, but ultimately treats it as one big bank from a load perspective.

Obviously, someone starting from scratch doesn't have to consider this. They can just do all LTO. Likewise, someone with LFP could consider selling it to replace with LTO. I'd personally rather add and find solutions to differences.

Your data is very useful. I look forward to your complete testing report.

 

[Craig]

If you are looking at 12V, then 6S certainly makes more sense. But, 11S can work well with 24V. I personally don't like getting too close to the lower limit of cells. I'd rather have a buffer down there for one-off situations.

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You make a good point one of the problems I do have is that once they hit bottom the drop off a cliff. Maybe 11 is ok then I was planning on cutting off at 24 V. in the end Im not sure if its a big difference or not the extra cells I will just put in parallel anyhow and all in all the capacity will be the same weather its 12P11S or 11P12S . Either way Im happy to be able to discuss this with others and learn!

 

[erik.calco]

You make a good point one of the problems I do have is that once they hit bottom the drop off a cliff. Maybe 11 is ok then I was planning on cutting off at 24 V. in the end Im not sure if its a big difference or not the extra cells I will just put in parallel anyhow and all in all the capacity will be the same weather its 12P11S or 11P12S . Either way Im happy to be able to discuss this with others and learn!

Yeah. This is great learning for us. Glad we can talk it through together. This does branch us into other topics we'll one day need to discuss in more detail, like how to add to current systems. That road will get very diverse in requirements. But, the principles will overlap. In this case, managing and optimizing within voltage ranges of the bank.

I really love the potential of LTO. Its adoption will likely drive a lot of these new discussions.

 

[thedodgersonline]

for 12v you will need 6 cells its a LTO thing and yes parallel them first then in series so you only need 1 bms

The challenge is in finding a LTO compatible BMS that does 6S. I have only found 5S. You would need to edit the charge volts as well because a fully charged LTO in 6S is 15.6v and LTO in 5S is 13v. This is generally enough for most 12v systems though.

 

[thedodgersonline]

I have 100 cells purchased direct from China Testing each one to make sure packs are balanced.

These are new cells with no wear and tare on them

From which dealer and what brand. I am looking at YinLong at the moment.

 

[erik.calco]

The challenge is in finding a LTO compatible BMS that does 6S. I have only found 5S. You would need to edit the charge volts as well because a fully charged LTO in 6S is 15.6v and LTO in 5S is 13v. This is generally enough for most 12v systems though.

Don't most cheaper 12V inverters have an upper limit of 15V? This is why 3.7V cells (4.2V is FULL) are usually done with 3S instead of 4S.

 

[Craig]

From which dealer and what brand. I am looking at YinLong at the moment.

I have yin long not happy with my dealer gonna try a new one on next batch 35% of my cells so far don't reach 40Ah capacity. Dealer says they are all good I say no.

 

[Craig]

The challenge is in finding a LTO compatible BMS that does 6S. I have only found 5S. You would need to edit the charge volts as well because a fully charged LTO in 6S is 15.6v and LTO in 5S is 13v. This is generally enough for most 12v systems though.

The chargery and I think the tiny bms will do up to 16 cells. But you do not have to use them all so you can do 12 cells on 16 cell BMS for instance

 

[thedodgersonline]

Don't most cheaper 12V inverters have an upper limit of 15V? This is why 3.7V cells (4.2V is FULL) are usually done with 3S instead of 4S.

I will be building my first ones as 12v camping battery so no inverter will be used. I am a bit nervous of putting 15.6v onto 12v appliances.

 

[thedodgersonline]

The chargery and I think the tiny bms will do up to 16 cells. But you do not have to use them all so you can do 12 cells on 16 cell BMS for instance

Really? I thought you had to use all the wires as the BMS needed to see a voltage on every I put. No voltage = flat cell = no output.

 

[thedodgersonline]

The chargery and I think the tiny bms will do up to 16 cells. But you do not have to use them all so you can do 12 cells on 16 cell BMS for instance

Thanks for the input. The Chargery looks the goods alright. Will check out the Tiny as well.

 

[Craig]

Really? I thought you had to use all the wires as the BMS needed to see a voltage on every I put. No voltage = flat cell = no output.

It lets you tell it how many cells to count

 

[Craig]

I will be building my first ones as 12v camping battery so no inverter will be used. I am a bit nervous of putting 15.6v onto 12v appliances.

you could charge them to only 2.45 volts and only lose a small percentage of overall capacity